Ladders and method of making the same



Feb. 9, 1965 R. H. SHAVER 3,163,938

LADDERS AND METHOD OF MAKING THE SAME Filed Jan. 4, 1963 2 Sheets-Sheet 1 a F/Gf 2 A TTOR/VE V1.9

Feb. 9, 1965 R. H. SHAVER 3,163,938

LADDERS AND METHOD OF MAKING THE SAME Filed Jan. 4, 1963 2 Sheets-Sheet 2 FIG 4 FIG. 5

wamw United States Patent Ofitice messes Patented Feb. 9, 1565 3,168,938 LADDERS AND METHQD F MAKE? rem SAME Raymond H. Shaver, Newark Valley, N.Y., assignor, by

mesne assignments, to Harsco Corporation, a corporation of Delaware Filed Jan. 4, 1963;, Ser. No. 249,479 2 Claims. (63!. 1E2-228) The present invention relates to ladders and method of making the same.

Ladders of traditional types and materials have, for many purposes, been too heavy it made suiliciently strong; or, if made of lighter weight materials, have lacked necessary strength or durability. It has not been feasible merely to substitute in known structures a L ghter material, as fiberglass, plastic or aluminum in place of Wood or heavier metal because, for some applications in use, the latter structure is thus materially weakened.

An object of the present invention has therefore been to provide a ladder of novel construction which permits the use of light weight materials with no consequent undesirable weakening or lack of durability. Further, it is contemplated that ladders embodying this invention may be made at reasonable cost from relatively light weight materials which are in abundant supply and may be transported at favorably moderate rates because of their light weight and sturdy construction.

In general, a ladder according to the present invention comprises side rails which may be open channels, or which may be of the box type, is. tubular members of light Weight material, assembled with tubular rungs of light weight malleable metal, as aluminum or an appropriate alloy thereof, with the rung ends rigidly engaged in web portions of said side rails.

in constructing such a ladder, the opposed side rail webs are provided with coaxial holes; and the rungs are deformed to produce thereon peripheral beads spaced from their ends. These rails and rungs are assembled with the rung ends engaged in said holes and with the beads bearing against portions of the webs which surround the edges of said holes. Each thus engaged end of said rungs is swaged, crimped, expanded or otherwise deformed to provide an end flange which, with said bead, serves to clamp the adjacentrung end securely to the side rail. In assembling rungs with box type rails, i.e. of tubular cross sectional contour, an interior spacer is positioned prior to said deformation to embrace that portion of each rung end'which lies Within and extendsbetween the opposed walls of. the rail; and in some instances, said spacer is deformed at least in part along with deformation of the rung end.

Other objects and important features of the invention not above referred to will appear in the following description and. claims and from the accompanying drawings wherein I have shown a preferred embodiment of the invention andhave described the same in this specification. It is to be understood that these disclosures are not intended to be either exhaustive or limiting or" the invention, but on the contrary, are presented for the purposes CAD of illustration so that others skilled in the art may so fully understand the same, its principles and the application thereof, that they may embody it and adapt it in various forms each as may be appropriate to the requirements of a particular purpose in use.

Referring to the drawings:

FZGURE 1 is a fragmentary View partly in section showing a portion of a b A type or tubular ladder side rail, an end portion of a rung engaged the ewith, and a tubular spacer in process of being moved into position on the end of said rung;

FEGURE 2 a fragmentary view partly in section of the parts shown in FIGURE 1 after the rung end and the spacer have been deformed to modified contours, as by swaging, crimping or the like;

FIGURE 3 a modification wherein the box type side rail is employed. The parts are here shown. with one end Wall member not yet assembled with the side walls to permit placing of the spacers on the rung ends between said side walls, the parts being shown with the spacer coaxially arranged in relation to opposed coaxial openings in the side walls of the rail and with the rung end in process of being moved into operative position in said spacer and said holes;

FIGURE 4, a fragmentary view of the parts seen in FIGURE 3 after the rung end has been deformed to clamp the spacer in Wall reinforcing position in the side rail; and the end wall has been applied to close the end opening between said side walls.

FIGURE 5, a modification partly in longitudinal section showing the step of moving a spacer into coaxial relation to opposed holes in a box type rail having a continuous unitary tubular wall open at its top and bottom ends, by means of a pusher actuated from one of said ends; and

FIGURE 6 is a tragmentary view partly in section of an open type channel side rail with a rung end crimped to form a bead and an end flange in clamping engagement with the peripheral edge of a hole or opening in the channel web.

To produce the completed ladder structure shown in FIGURE 2, I provide the webs (a) and (b) of opposed side rails, as the unitary tubularbox type rail It), FIGURE 1, with opposed coaxial holes, one of which, as 11 in web (a) is of smaller diameter than the other, as 12 in web (b). A head 13 is formed, as by crimping, near the end of tubular rung 14 which may advantageously be of malleable metal, such as aluminum or aluminum alloy; and said side rails may be of suitable light weight but strong material as fiberglass, aluminum, etc. This end of said rung beyond the head 13 is moved in the direction of the arrow at the right, FIGURE 1, through openings 11 and 12 to bring head 13 snugly against the outside face of web (a); and spacer 15 may be moved through opening 12 in the opposite direction, i.e. that of the arrow at the left, FIGURE 1, either along with the entering movement of the run end or after said end has reached the position shown in FIGURE 1. Or, Where rung 14, prior to assembly, has no abutment or head 13 adjacent its ends, the end portion is engaged in the laterally spaced embracing said end between said walls.

opposed openings 11 and 12 in the inner and outer walls, a and b, respectively, of the rail and with a spacer 15 Bead 13 and flange 13, for example, may now be formed against said rail walls by securing rung 14 against endwise displacement while pressing, hammering or otherwise deforming said end portions to produce the desired abutments or beads while said spacer 15 prevents collapse of the rung end between the walls of the rail. In either case, when spacer 15 reaches the dotted line position shown in said figure, known mechanical devices and procedures are employed to expand the rung end and said spacer 15 to suitable outwardly flared contours, FIGURE 2. This expansion effected by pressure forging for example, along with spinning, swaging, or the like, drives the flared portion of the rung end into secure engagement with the edge of opening 12 which is advantageously interrupted by a notch 1s. A portion of the displaced metal of said rung end effected by said forging, or the like, flows into said notch 16 to form a key 17 thus, in eflect, locking the rung 1d I against rotation. Deformation of the rung end also produces a terminal flange, 18, FIGURE 2, which, with head 13, serves to clamp rung 14 securely in operative relation to rail 10,

The deforming or crimping operations just above referred to involve application of substantial axial pressures. It is therefore contemplated that the rail walls will be materially reinforced to withstand said pressures by providing the spacer 15 of suitable material and dimensions. When placed as seen in FIGURE 1 (dotted) said spacer prevents collapse of the rail walls under pressure while permitting deforming or metal flowing forces to operate efiectively and thereby produce the joint structure of FIGURE 2.

It is apparent that spacer 15 in the deformed condition seen in FIGURE 2 and cooperating with head 13 and flange 18 also permits rung 14 tobe clamped securely to both webs of rail 10 and counteracts any weakening effect of the holes 11, 12 therein.

A modified form of structure as seen in FIGURE 4 also employs a box type side rail 21 which, instead of being a unitary tube, as in FIGURE 2, is a composite tube com- 1.

prising spaced webs 21 and 22 and end or edge channels 23, 24. Said webs are provided with opposed coaxial I (upper FIGURE 3) is left open. Spacer 28 is inserted through said opening in the down direction of the arrow FIGURE 3 to a position wherein it is coaxial or in register with the holes 25, 26.

;While said spacer is in this position, the end of rung 14 is moved inthe direction (left) of the arrow, FIGUREB, through opening 25, through the spacer 28 and through opening 26 to an extent which brings head 13 snugly against the outside face of Web 21 and brings the end of rung 14 beyond the outside face of web 22. Thus, spacer 28 is positioned on an end portion of rung ldbetween and engaging opposed portions of the inside faces of webs 21 and 22. Suitable forces are now applied, as spinning, swaging, crimping or the like, to form a terminal flange 29, FIGURE 4, on the end of rung 14, meanwhile applying pressure to clamp a portion of web 21 between bead 13 and spacer 23 and a portion of web 22 between flange 29 and said spacer. In the course of these operations, a portion of metal of the engaged rung end is caused to flow outwardly into notch 27 to form a detent or radial key 30 in said notch and thus to anchor rung 14 against rotation in holes 25 and 26. When the desired number of A rungs have been mounted in the rail 20 as above described, the end channel 23 is applied to close the longitudinal opening between the webs 21 and 22 where it is secured by any suitable means, as welding, not shown. In the just described structure, the spacer and other parts have functions corresponding to those noted in connection with the FIGURE 2 embodiment but with no flared out deformation of the rung and spacer.

The procedure illustrated in FIGURE 5 applies to the making of a ladder wherein the rails are of the box type, such as continuous or unitary tubes 10, as indicated in FIGURES 1 and 2 for example. However, the rail 10, FIGURE 5, has holes 31, 32 of the same diameter, approximately that of the outside of the rung14. To bring a spacer, as 28 into register with holes 31 and 32, said spacer is engaged with a suitable pusher including a head 33 and a handle 34. Said head with a spacer in operative relation thereto is extended into rail 10 through its open (lower) end as seen in FIGURE 5 until the spacer reaches the desired position in register with holes 31, 32. While the spacer is so positioned, rung 14 is moved in'the direc tion (left) of the arrow FIGURE 5 to its dotted line position as there indicated. Subsequent operations as spinning, crimping, swaging or the like are carried out as described in connection with the FIGURE 4 embodiment and with equivalent results.

In a modification, FIGURE 6, involving an open type or channel rail 40, the web 41 thereof is provided with a hole 42 having a diameter substantially that of rung 14. In this case, the end portion of rung 14 is extended through hole 42 to an extent to bring bead 13 snugly against the outer face of said web 41 and to bring the end of said rung beyond the inner face of said Web 41. While the parts are held securely in this relation, forces are applied in a known manner to said extended end to form a terminal flange 43 and to press a portion 44 of the metal of rung I4 into'notch 27. Or, where the mug is not initially beaded, both said be-ad 13 and said flange 43 may be formed 'with the rung in operative position and substanflange 43.

From the foregoing it is apparent that the structures and procedures described above are well suited to, attain the ends and objects herein suggested or directly set forth;

vthatsaid structures can be manufactured and said method be practiced readily by conventional fabrication tech! niques; and that the various features and arrangements of parts and steps of method can be modified so as best to suit a particular purpose or use. Certain features of the disclosure maybe used to advantage in particular applications without a concurrent use therewith of other specific features; and the elimination or modification of such specific' features from an embodiment or procedure. is to be construed as bringing such apparatus or method within the scope of this invention, unless specifically excluded by the terms of the following claims or required by the state of the prior art.

I claim:

1. Ladder construction comprising a tubular side rail provided with opposed coaxial holes, one of'said holes 'having a notched portion in its periphery, a rung having extending peripheral inner flange longitudinally spaced therefrom, said outer flange being flared first outwardly and then inwardly and part of said outer flange projecting radially into said notch portion of said notched hole to lock said rung against rotation in said holes and said flanges being arranged opposite the ends of said spacer whereby the latter is effectively clamped by said flanges between opposed portions of the rail wall which define said holes.

2. Ladder construction according to claim 1 and wherein said notched hole is of greater diameter than the other hole, and said rung end and said spacer are flared radially in the direction from the smaller diameter hole toward the larger diameter hole.

References tilted in the file of this: patent UNITED STATES PATENTS 

1. LADDER, CONSTRUCTION COMPRISING A TUBULAR SIDE RAIL PROVIDED WITH OPPOSED COAXIAL HOLES, ONE OF SAID HOLES HAVING A NOTCHED PORTION IN ITS PERIPHERY, A RUNG HAVING AN END EXTENDING THROUGH SAID HOLES AND ENGAGING THE HOLE DEFINING EDGE SURFACES THEREOF, SAID END RUNG BEING ADJACENT SAID NOTCHED HOLE, AND A RAIL REINFORCING TUBULAR SPACER MOUNTED WITHIN THE RAIL IN CONTINUOUS SURFACE CONFORMING RELATION TO THE PERIPHERAL SURFACE OF SAID RUNG END AND ARRANGED WITH ITS OPPOSITE END FACES ABUTTING OPPOSED UNDERFORMED INTERIOR FACE PORTIONS OF SAID RAIL WHICH ENCIRCLE SAID HOLES, SAID RUNG HAVING A RADIALLY EXTENDING PERIPHERAL OUTER FLANGE FORMED AT ITS END AND A RADIALLY EXTENDING PERIPHERAL INNER FLANGE LONGITUDINALLY SPACED THEREOF, SAID OUTER FLANGE BEING FLANGED FIRST OUTWARDLY AND THEN INWARDLY AND PART OF SAID OUTER FLANGE PROJECTING RADIALLY INTO AND NOTCH PORTION OF SAID NOTCHED HOLE TO LOCK SAID RUNG AGAINST ROTATION IN SAID HOLES AND SAID FLANGES BEING ARRANGED OPPOSITE THE ENDS OF SAID SPACER WHEREBY THE LATTER IS EFFECTIVELY CLAMPED BY SAID FLANGES BETWEEN OPPOSED PORTIONS OF THE RAIL WALL WHICH DEFINE SAID HOLES. 